The present invention relates to techniques for performing oilfield operations relating to subterranean formations having reservoirs therein. More particularly, the present invention relates to techniques for performing adaptive drilling operations based on predetermined and updated wellsite parameters.
Oilfield operations are typically performed to locate and gather valuable downhole fluids. Typical oilfield operations may include, for example, surveying, drilling, wireline testing, completions, production, planning, and oilfield analysis. One such operation is the drilling operation which involves advancing a drilling tool into the earth to form a wellbore. Key to the drilling operation is determining where and how to drill the wellbore.
Before drilling begins, a field development plan (FDP) may be prepared to define how the drilling operation will be performed. Data concerning a proposed field is considered, and an FDP designed to meet certain objectives for the field, such as maximizing value (e.g, maximum NPV), and reaching optimal reservoir locations. The FDP may include various operational specifications for performing drilling and other oilfield operations. For example, drilling specifications may specify items, such as platform locations, well or borehole trajectories, wellbore capacity, completion type, location, equipment, and/or flow rate.
While the FDP may provide a good plan for initiating drilling and other oilfield operations, many uncertainties may exist and events may be encountered during the actual drilling that could not be predicted. These uncertainties include drilling issues, such as hazards (e.g., obstacles, pressure kicks, failures, conflicts, geological abnormalities, etc.), constraints (e.g., physical, engineering, operational, financial, legal, etc.) and/or losses (e.g., equipment failure, blowouts, mud losses, equipment damage, missed targets, etc.) Attempts have been made to provide advanced techniques for making plans and predictions as described, for example, in U.S. Pat./Publication Nos. 2009/0260880, 2008/0300793, 2007/0285274 and 2005/0114031, as well as GB Patent No. 2405205.
Despite the existence of techniques for enhanced drilling operations there remains a need to design drilling operations based on a better understanding of the wellsite. It is desirable that such techniques take into consideration the effects of various stages of the drilling operation. It is further desirable that such techniques avoid certain drilling issues that may affect the efficiency of the drilling operation. Such techniques are preferably capable of one or more of the following, among others: optimizing drilling, optimizing objectives (e.g., NPV), reducing costs, reducing risks, reducing uncertainties, collecting data in real time, analyzing data in real time, updating operations in real time, adjusting operations in real time, providing a reliable analysis, providing efficient data acquisition, providing real-time characterization of the near well bore environment, providing real-time well plan updates, performing reliable interpretations sufficiently rapidly so as to be able to influence major decisions while drilling, setting casing in competent rock, preventing hazards and/or damage, dealing with constraints and providing trajectory control. Real-time may mean during the course of drilling, and may include any data collection and/or data analysis while drilling or during the course of drilling the well.